The present invention relates generally to fluid handling apparatus and, in particular, destructible or deformable element controlled valves.
It is difficult to produce oil and gas in an economic manner from low permeability reservoir rocks. Production rates are often boosted by resorting to hydraulic fracturing, a technique that increases rock permeability by opening channels through which hydrocarbons can flow to recovery wells. During hydraulic fracturing, a fluid is pumped into the earth under high pressure where it enters a reservoir rock and fractures it. Proppants are carried in suspension by the fluid into the fractures. When the pressure is released, the fractures partially close on the proppants, leaving channels for oil and gas to flow.
Specialized pumps are used to develop the pressures necessary to complete a hydraulic fracturing procedure or xe2x80x9cfrac job.xe2x80x9d These pumps are usually provided with so-called fluid ends within which reciprocating plungers place frac fluids under pressure. On rare occasions, enough proppant can become trapped or captured within a fluid end to block the flow of fluid from it, sometimes leading to catastrophic pump failure. A need exists, therefore, for a product that will prevent the buildup of excessive pressures within the fluid end of a pump in the event of a flow blockage.
In light of the problems associated with conventional oilfield pumping equipment, it is a principal object of the present invention to provide a pressure relief valve that can be easily installed in the fluid end of a conventional, high-pressure pump to vent fluids in the event that pressures exceeding a predetermined threshold are reached. The preferred pressure relief valve permits the pressure threshold to be set by a user so as to ensure maximum safety in any operating environment.
It is another object of the invention to provide a pressure relief valve of the type described that can be readily sized for installation in fluid ends of numerous makes and models. The pressure relief valve can also be installed and serviced with minimal training and with conventional tools. Should the pressure relief valve ever open to relieve pressures in an abnormal situation, it can be rapidly returned to use with the replacement of an expendable part.
It is a further object of the invention to provide a pressure relief valve whose fluid discharge can be directed into an area selected by a user.
It is an object of the invention to provide improved elements and arrangements thereof in a pressure relief valve for the purposes described that is lightweight, inexpensive to manufacture, and fully dependable in use.
Briefly, the pressure relief valve in accordance with this invention achieves the objects noted above by featuring a cage for positioning within a passageway connecting an area of high pressure with an area of low pressure. The cage includes a valve seat having a central channel open to the area of high pressure and a valve seat retainer abutting the valve seat and having a plurality of peripheral channels open to the area of low pressure. The central channel is normally blocked by the head of a deformable plug positioned within the cage between the valve seat and the valve seat retainer. A hollow, bulbous tail extends from the head and abuts the valve seat retainer. Deformation of the tail moves the head away from the seat thus permitting fluid to move from the area of high pressure through the central and peripheral channels to the area of low pressure. A deflector is carried by the valve seat retainer to direct the flow of fluid from the peripheral channels into the area of low pressure.
The foregoing and other objects, features and advantages of the present invention will become readily apparent upon further review of the following detailed description of the preferred embodiment as illustrated in the accompanying drawings.